Apparatus for separating gold from sand.



Patented lune`5, |900.

J. P. STERLING. APPARATUS FUR SEPARATING GOLD` FROM SAND.

(Application filed-Dec. 9, 1899.)

3 Sheets-Sheet I.

(No Model.)

sirens co. wom-uwe., wAsHmGvon. u c.

Patvnted June 5, |900.

J. P. STERLING.

APPARATUS FUR SEPARATI-NG GOLD FROM SAND.

(Application led Dec. 9, 1899.)

(No Model.,l 3 Sheets-Sheet 2.

/f//f ff mz Nonms Pfrzns co, PHoTovuwo., wAsHmGYoN. D. c.

No. 65|,o22. Patented :une 5, |900.

J. P. STERLING.

APPARATUS FOR SEPARATING GULD FROM SAND. (Application fixed me. 9,1899.)

(No Model.) 3 Sheets-Sheet 3.

UNITED STATES' PATENT einen'.

JOI-IN P. STERLING, OF KANSAS CITY, MISSOURI.

-APPARATUS FOR SEPARATING GOLD FROM SAND.

SPECIFICATION forming part of Letters Patent No. 651,022, dated June 5,1900.

Application tiled December 9. 1899. Serial No. 739,831. (No model.)

To all whom it may concern:

Beit known that I, JOHN P. STERLING, acitizen of the United States,residing at Kansas City, inthe county of Jackson and State of Missouri,have invented a new and useful Apparatus for Separating Gold from Sand,of

kinds of gold to successfully separate from sand and other refusebecause its specific gravity is lighterv than the sand in which it iscontained; but by myinvention I am able not only to separate the largerparticles, known as shotand flake gold, from the sand, but also tothoroughly-eliminate the sand from the extremely-fine particles offlour-gold, the latter being collected and finally delivered in thecondition similar to an impalpable powder. v

One object of the invention is to provide a simple apparatus designed toattain the purposes hereinbefore briefly enumerated, in which apparatusthe shot and flake gold are separated at the first stage of theoperation from the sand, while the sand and foreign matter areeliminated from the flour-gold during the remaining steps of thetreatment.

A further object is to provide means for disintegrating-and separatingthe crude material as it is found in its natural condition with a viewto cleaning the same from foreign matter in order that'themineral-bearing sand only may be supplied to the apparatus forpneumatictreatment therein.

A further object is to provide a novel system for the treatment ofgold-bearing sand in which the gold is graded according to the size ofits particles at a preliminary stage. Certain ofthe grades of gold andthe sand are subjected to a reduction operation, and each grade istreated pneumatically for the thorough elimination of sand from theprecious metal, and the latter is collectedand discharged in a purecondition entirelyfree from foreign matter.

With these ends in view the invention consists in the construction andarrangement of parts and in the novel combinations of mechanisms, aswill be hereinafter fully described and claimed.

Inl the accompanying drawings I have represented an apparatus forseparating gold from sand which embodies the several features of myinvention in their preferred form, and to these drawings I ,shall nowre- `fer in order to explain more4 clearly the nature of the inventionand the manner in which the same is or may be carried into effect.

Figure l is a sectional elevation taken vertically and longitudinallythrough my apparatus, which is shown asv connected operatively with amachine known in the art s a dust collector, said apparatus beingequipped with a revoluble screen as one means for cleaning thegold-bearing sand from foreign mattei'. Fig. 2 is an enlargedlongitudinal section through the rotary screen removed from theapparatus and showing the means by which the gold-bearing sand in itsnatural condition may be supplied to the screen and the refuse may bedischarged therefrom, the parts of the screen being arranged to spreadthe gold-bearing sand along the length of the screen and discharge thevsame in asheet-lke condition or cloud directly into the path of the airsuction-current of the apparatus. Fig. 3 is a vertical vtransversesection through said screen in the plane of the dotted line 3 3 of Fig.2.

Fig. 4 is a similar transverse section in the plane of the dotted line 44 of Fig. 2. Fig. 5 is a vertical sectional elevation through theapparaftus 'similar to Fig. 1, but representing an- .other type ofscreen mechanismfor cleaning the refuse from the gold-bearing sand anddischarging the latter in a sheet-like condition directlyin the path ofthe air suction-current. Fig. 6 is a sectional elevation of a systemembodying means for grading the gold according to the size of theparticles and for pneumatically treating the different grades of goldindividually in accordance with myinvention. The same numerals ofreference are'used to indicate like and corresponding parts in each ofthe several figures of the drawings.

10 designates the casing of my apparatus ICO for pneumatically treatinggold-bearin g sand in accordance with the principles set forth. Asshown, this casing is of substantially-rectangular form, although itscontour is immaterial. end of this casing is provided an offsetscreenhousing 1l, which may be of any suitable.

tion-inlet port 13 to the apparatus is pro' vided in the vertical frontwall of the casing l() at a point below the lower inclined wall orbottom of the screen-housing, reference being hadV more particularly toFig. 1. Vithin the casing and contiguous to the front walls thereofandthe screen-housingis a verti- -ffgcalp-arti'ticner wall 14,the upperpart of which has two inclined sections 15 1G. The vertical part of thewall is parallel with the front of the casing, so as to form below theinlet-port 13 a collecting-pocket 17, in which may accumulate theheavier particles of gold known as the shot and flake gold, as willhereinafter appear. The Vertical stationary wall or partition 14 facesor lies opposite to the inlet-port 13; but the inclined sections 15 16are in the horizontal plane of the screenhousing 11, whereby theinclined portions or walls 15 1G and the screen-housing form a primarytreatment-chamber 1S, the area of which greatly exceeds thecross-sectional area of the passage or chamber formed at the front partof the casing 10 in the plane ofthe inlet-port 13.

The pocketv 17 is closed at its lower end by a Hap-valve 19, which isheld normally in a closed position and is adapted to open automaticallybythe weight of the shot'and ilake gold which accumulate in said pocket,thereby discharging the contents by gravity from the pocket.

The inclined sect-ion 15 of the wall is arranged at an angle to thesection 1-1 and to the vertical plane of the screen mechanism in thechamber 1S, said inclined section 15 lying inthe plane below thehorizontal plane of the axis of the screen. This inclined wall 15 liescontiguous to the screen mechanism, so that the gold-bearing sand willbe discharged from said screen mechanism toward or upon the wall 15, andthis screen mechanism is thus arranged to discharge the goldbearing sanddirectly into the space or airpassage which is formed on one side by thewall 15. The screen mechanism which I employ operates, essentially, tospread the goldbearing sand in a sheetlike condition or cloud and todischarge the same directlyinto the path of the suction-current of airwhich At the upper corner ot' the receiving`"` is created through theapparatus, so as to have its intake at the port 13, whereby the suctioncurrent is of greatest or highest strength at the place where thegold-bearing sand :is discharged thereinto by the screen mechanism. Thiswall 15 is adjustablysupported in place by anysuitablemeans-such, forexample, as the hinge Z0-and to the wall is connected one end ot' anadjusting-rod 21, that passes to the outside of the casing and is heldin place by any suitable means--such, for example, as the thumb-nut 21a.The inclined wall 16 is arranged reversely to the inclined wall 15, andthe two walls occupysuch relation to each other as to produce an airport22 at the angle or corner formed by such reversely-inclined walls, andacross this airportl is arranged a screen 23, of any suitable foraminousmaterial, the same being secured to the fixed wall 1G or the casing inany appropriate way. The inclined wall 15 may be adjusted relatively t-othe screen so as to vary the cross-sectional area of the air passage .orchamber between said screen and the wall 15, thus serving in a measureto regulate the strength of the current and the inclination of the wall15 relative to the vertical partition 14. The screen 23 has meshes ofsuitable size to catch and arrest the larger particles of flake-gold,which are carried by the suction-current and the gold-bearing sand in anupward direction through the chamber 17 and into or through the port 22.It is to be understood that Hake-gold and shot-gold arc of higher orgreater specific gravity than the sand in which the gold is contained,it being estimated that gold ol' this character is approximately ninetimes heavier than sand. At the initial stage of the pneumatic treatmentof the gold-bearing sand immediately following its discharge from thescreen mechanism and'at the period when it is subjected to the strongestaction of the air suctioncurrent the sand, the Hake-gold, and the Hourgold will be caught up by the current, inasmuch as the materials aredischarged in a sheet-like condition or cloud into the path of theair-current. This operation is important in the pneumatic treatment olthis particular material because it eects two necessary steps-to wit,first, the shot-gold being considerably heavier than the other particlesof gold and sand will drop or fall by gravity through the passage oralong the wall 15, so as to accumulate in the pocket 17, and, secondly,the flake-gold will becaught or arrested by the screen 23, so that theparticles of flake-gold will liow or drop by gravity along t-he inclinedwall 15 and into the pocket 17, thus thoroughly separating the shot-goldand the Hake-gold at the initial step ot treatment of the material andcollecting gold of this character in the first pocket ol the apparatus.The remaining steps ot' the treatment of the material are directed tothe thorough elimination of the particles ot sand from the flour-gold,which, as hereinbet'ore stated, is of lighter spejciiic gravity than thesand and is the most difficult of all particles of gold to collect,either bythe hydraulic washing process, a mechanical dry separation, orby treating the materials pneumatically.

ln my apparatus I ha-ve constructed the casing to form a series oftortuous circulation-passages, in which the air-'current is caused toascend and descend alternately through chambers or passages ot' varyingcross-sectional area, in order to gradually weaken the strength of theair-current as it progressively traverses the chambers or passages, ajndthereby precipitate or allow the particles of sand -to drop by gravity,while at the vsame time effecting the im portant purpose of carrying ottthe extremely tine and light particles of flour-gold with theair-current. Vertical walls or partitions 24 depend from the top of thecasing to suitable points near the bottom thereof, and other verticalwalls or partitions 25 extend upwardlyfrom the bottom of the casing topoints close to the top thereof. The walls 25 are disposed close to thewalls 24, so as to form the upward circulation-passages 27 2S betweenthe two pairs.

of walls 2425; but the first upward passage 27 is of lesscross-sectional area than the second upward circulation-passage28.Another vertical wall 29 is arranged parallel with the back of thecasing, so as to form an upward circulation-passage 29, whichcommunicates directly with the eye in the casing of a suction-fan. Thespace between the -walls 25 24 provides a drop-passage 30, the area ofwhich is considerably kgreater than the first upward circulation-passage27 and is also of greater area than the second upward passage 28, and asimilar drop -passage 31 is provided between the wall 29 and the secondwall 25, the cross-sectional area of which passage 31 is equal to thatof the first drop-passage 30. The final uptake-passage 29L is greaterthan that ofthe intermediate uptakepassage 28, and thus the series ofuptakepassages increase progressively in cross-sectional area from thefront to the rear of the casing. The walls 24, 24, and 29 are providedwith the airports 32, 33, and 34, respectively, which establishescommunication from the drop-passages to the uptake-passages, and overthese ports are inclined the battles 35, which prevent certain parts ofthe material from being carried with the air-current into certain of theuptakepassages. At the bottom of the passage 14, between the walls 1424, is an inclined bottom 3G, and a similar bottom is provided at thelower end of the drop-passage 30. The other drop-passage 3l has a bottom37, which is inclined toward the bottom 36 of the passage 30. The bottom36 of the passage 14 inclines toward the first wall 25, so as to formy apocket 38, and the bottoms 3G 37 of the passages 30'31, respectively,form between themselves a pocket 39. In thebottom of the passage 29a isa wall similar to the walls36 and forming in the tinal uptake-passageanother pocket38. In each of these pockets, at the lower ends of thedroppassages, is a flap-valve 40, held closed by a suitable spring andadapted to be opened automatically by the gravity of the materialaccumulating in the passage.

The inclined bottom of the screen-casing is extended inwardly to a pointbeyond the vertical plane of the front wall of the casing, therebyforming a detiector 41, adapted to direct any material from the screenmechanism which lodges upon the inclined bottom of, the casing directlyinto the path of the aircurrent drawn into the port 13, and this de-Hector lies below the plane of the hinge-joint for the inclined wall 15,whereby the particles of gold which traverse the wall 15 lodge upon thedetiector 41 and are prevented from dropping through the port 13. Thearea of this inlet-port may be varied to regulate the volume of air andthe strength of the current by any suitable form of valve, one type otwhich is represented as a slide-valve 42, held in operative relation tothe port by suitable guides.

The casing 44 of the suction-fan 43 communicates directly with the upperend of the final uptake-passage 29, and from this suction -fan casingleads a flue 45, which communicates directly with the central port oreye of a machine known in the art as a dust-collector and which isdesignated in its entirety by the numeral 4G in Fig. 1 of the drawings.The rotation of 'the suction-fan at high speed creates a suction-currentthrough the apparatus. The air is drawn in at the port 13 and passesupwardly through the chamber 18 to the port 22, from whence thecurrentdescends through the passage 14a to the port 32, thence passes inan upward direction through the uptake-passage 27, over the top edge ofthe first wall 25, thence descends through the drop-passage 30, passesthrough the port 33, traverses an upward course through theuptake-passage 28, over the top edge of the second wall 25, then passesin a downward direction through the final drop-passage 3l,then passesthrough the port 34, and nally makes its escape through theuptake-passage 29 into the eye of the fan-casing. The suction-currentthus pursues a tortuous course in alternately upward and downwarddirections through the circulation-passages of the apparatus, and thisis im portant, because the sand is wholly eliminated from theiiour-gold'before the latter is carried along with the aircurrent intothe suction-fan, from whence the deur-gold is blown into thedust-collector. As hereinbefore described,the shot-gold gravitates orfalls into the pocket 17 at the initial stage ot the treatment, whilethe iiake-gold is carried along with the sand and the aircurrent in anupward direction through the chamber 1S until it strikes the screen 23,the latter arresting the further progress of the flake-gold with theair-current and causing gold of this character to finally lodge in thepocket 17. The sand and the extremely-fine particles of flour-gold arecarried by the aircurrent through the successive passages, whichincrease in area, so as to effect a reduction in the strength of thecurrent gradually, and this course of the circulation and the gradualreduction in strength permit the heavy and light particles of sand togravitate as the current pursues its course through the passages 14, 27,30, 2S, 3l, and 29% The particles of sand accumulate mostly in thepockets 38 39 at the bottom of the passages 14, 27, 30, 38, and 31, itbeing found that very little sand and that of the lightest characteraccumulates in the pocket of the passage 29.

It will be observed by reference to the drawings that the ports whichestablish communication between the vertical uptake-passages and thedropepassages, as at 32 33 34, are at some distance above the bottoms ofthe drop-passages, this construction causing the air-current to set upeddies in the lower portion of.' the drop-passages, which eddies greatlyfacilitate the precipitation of the sand. The baffles 35 above the saidports serve to divert the down-current in the drop-passages from thewalls thereof toward the central portions of said drop-passages, thuscausing the particles of sand and gold to be more thoroughly exposed tothe action of the current. The inclined bottoms of the drop-passagescommunicate directly with the pockets formed at the bottoms of theluptake-passages, as shown. This construction is advantageous in causingthe sand as it is deposited on the bottoms of the drop-passages to passdirectly therefrom and accumulate in the pockets, hence keeping saidinclined bottoms of the drop-passages practically clear at all timesduring the operation of the apparatus and avoiding contraction of thearea of the drop-passages by the accumulation of sand therein, whichwould tend to the elimination of the eddies. It will be further observedby an inspection of the drawings that the uptake-passages alternate withthe droppassages and that the current after passing from a drop-passageinto an uptake-passage has to traverse practically the entire height ofthe lat-ter before reaching the next droppassage in series, thisalternating arrangement of the drop-passages and uptake-passages causingthe direction of the current to be reversed in said'passages andaffording an increased opportunity for the particles of sand to drop andbecome separated from the finer lighter particles of flour-gold duringthe ascent of the latter through the uptake-passages, hencegreatlyincreasing the efficiency of the pneumatic apparatus.

Although I have shown and described the dust-collector 46 ascommunicating with the exhaust of the suction-fan, it is evident thatthe fiour-gold in the form of an impalpable powder may be dischargedinto a closed receptacle adapted to collect the flour-gold, so

that it may be subjected to subsequent treatment-as, for instance, bythe well-known cyand process.

The screen mechanism which I employ may be either of the rotary type(shown by Figs. 1 to 4, inclusive,) or of the shaking-shoe variety,(illustrated by Figs. 5 and 6;) but in type of screen mechanism the sameis either arranged in the housing or hood 11, so as to discharge thematerial in a sheet-like condition into the chamber or passage 18 oragainst the inclined wall 15, such screen mechanism being essentiallyoffset into the chamber 18 for the purpose of dropping the materialdirectly into the path of the ascending suction-current.

I will first describe the special construction of the rotary screen, andit should be borne in mind that the gold-bearing sand is designed to bedistributed throughout the length of the screen in order that it may bedischarged in a sheet-like condition, as set forth.

The screen is designated inits entirety by the numeral 47, and at itsends said cylinder is `provided with the heads 48 49, said heads havingexit-openings in which are loosely fitted the troughs 55 58, that serveto assist in feeding and discharging the material to and from therevoluble cylinder in the plane of its longitudinal axis. A spider 50 isarranged equidistant from and between the two heads, and a series ofbands 5l are between the spider and the heads. The bands are equal indiameter to and arranged concentric with the heads, and these bands andthe heads are joined together by the longitudinal bars 52. The bands,however, are not connected directly with the bars, becausespacing-blocks 53 are arranged between the bars and the bands at thepoints where the bars intersect with the bands, whereby the bars areconfined within the plane of the cylindrical screen 54. This screen isfitted snugly around the heads and the series of bands, so as to be heldin a taut condition thereby, and by interposing the blocks between thebands and the connecting-bars 52 ample space is provided between thescreen and the bars for the distribution of the gold-bearing sandthroughout the length of the revoluble screen. The parts are securedfirmly together in any approved way, so as to renderthe screensubstantial in construction. The feed-trough 55 extends loosely throughthe opening of the head 49, so as to have its inner end terminateadjacent to the central spider 50, and said trough is provided withperforations 56 in its bottom and with a discharge-lip 57 at its innerend to insure the distribution of the sand through a part of thecylinder at its receiving end. rlhe discharge-trough 58 is Iittedloosely in an opening of the head 48, and it is provided at a pointexterior to the rotary screen with a spout 59, that carries away thetailings from the screen. A shaft 60 passes axially through the cylinderand the spider 50 thereof, said shaft also passing through IOO IIO

the feed and discharge troughs 55 58, respectively. This shaft carriesthe screw conveyers 6l 62, which are arranged'in the troughs 55 58,respectively, for the purpose of feeding the material into one end ofthe cylindrical screen and discharging the tailings from the other endof said screen, andthe two conveyers and the spider of the cylinder aremade fast to this shaft, which is j ournaled in proper bearings (notshown) of the screen-housing 11, one end of said shaft being providedwith a pulley, as indicated in Fig. 2 by dotted lines, for the purposeof rotating the shaft by a power appliance. The tailings which areretained or kept within the cylinder are lift-ed intov thedischarge-trough by suitable buckets G3, which rotate with the cylinder.These buckets are provided at the discharge endof the chamberand in theangle or corner formed by the cylindrical screen and the head 48, (seeFigs. 2 and 4,) and these buckets are open at one end for the lodgmentof material therein when the bucket is at the lower side of thecylinder, each bucket discharging its load by gravity into the trough 58when said bucket is at the upper side of the cylinder. I do not desire,however, to strictly confine myself to the rotary type of screenmechanism, because under some circumstances I may desire to employ theshakin g-shoe 65 (shown by Fig. 5 ofthe drawings) as the means forcleaning the gold-bearing sand and discharging the same in a sheet-likecondition into the path of the air-current. The housing or hood ll ofthe screen mechanism is shaped to correspond tothe style of screenmechanism, the chamber of said hood communicating directly with thechamber18 in order that the screen mechanism maybe offset into theprimary airchamber of the apparatus. This shoe is provided with one or aseries of screens 66, each provided at its discharge end with a trough67, adapted to deliver the tailings in any suitable way to the outsideof the hood. Theshoe is suspended by the hangers 68, (indicated bydotted lines in Fig. 5,) and in the hood is arranged a shoe-drivingshaft 69, the same being shown as provided With eccen'trics that actuatethe links 70, the latter being connected to the shoe. This shaking-shoeis supplied with the gold-bearing sand by the chute or other preferredmeans, so as to act on the same to separate the refuse from the sand anddischarge the latter into the chamber or passage 18. The pneumaticseparator shown by Fig. 5 is essentially the same in construction andoperation as the separator shown by Fig. l, and I do not, therefore,consider it necessary to again describe said pneumatic separator.

In treating the gold-bearing sand in large quantities and on an extendedscale I employ the system indicated by Fig. 6 of the drawings, Whichcontemplates grading of the ore according to size, crushing the ore andprecious metal of certain sizes, and pneumatically treating thedifferent grades of sand and kings to pass to the succeeding screens.

metal individually. In'this system I employ a primary receptacle, whichI prefer to designate as a grader 7l, which is equipped with a series ofscreens of different meshes, said screens being indicated at 72, 73, 74,and 75. The screens are arranged in alinement with each other or in thesame plane longitudinally of the grader, so as to occupy asubstantially-flush relation and permit the tail- The screen 72 hasmeshes which are very small, so as to permit the very line sand andflourgold to pass therethrough. The screens 73 and 74 are somewhatcoarser than the screen 72, and said screen 74 is coarser than thescreen 73, which precedes it, while the screen 75 has meshes of largersize than either of the preceding screens. The tailings from the graderare discharged at the tail end thereof after passing over the finalscreen 75, and the material is supplied in any suitable way to the headend of the grader, so as to lodge upon the fine screen 72. This gradermay be reciprocated or moved positively by any suitable mechanicalappliances, orit maybe arranged in a stationary inclined position forthe material to traverse the same by gravity. Said grader is provided onits under side with a series of hoppers 76, each of which receives thegoldbearing sand from the screen arranged'above lthe same, each hopperhaving a suitable opening 76a at its bottom for the proper discharge ofthe material from the screen. Below the series of hoppers provided onthe under side of the grader is arrangeda series of pneumaticseparators, (indicated by the numerals 77 78 79 80,) which are arrangedin such relation of the hoppers to the grader as to be suppliedindividually with the different grades of material through the medium ofthe spouts or chutes l2. Each pneumatic separator is constructed andadapted for operation in the manner heretofore described and isindicated by Figs. l and 5, and each separator operates independently ofevery other separator of theseries, so that the different grades of sandand gold particles therein will be subjected to treatment individually.This system, including the series of independent pneumatic separators,provides for regulation of the suction-currents in the series ofseparators of different strengths, so that each grade of gold bearingsand may be treated by a current of a strength suited to the particularmaterial. In order to more thoroughly separate the larger particles ofgold from the sand in some grades of material, I employ means forcrushing or reducing the coarse grades at a stage subsequent to thegrading thereof and before treating the same pneumatically. Between thehopper of the screen 73 and the separator 78 is disposed a pair ofcoacting crushing-rolls 81, which are arranged to receive the materialfrom the hopper of said screen 73 and re- TOO IIO

duce or crush the same before it passes into I the spout leading to theseparator 78. In like manner other pairs of rolls 82 83 are disposedbetween the sereen 74 and separator 7 9 and the screen 75 and separatorSO, respectively, whereby the eoarser grades of material are in likemanner Crushed or reduced before they enter the proper pneumaticseparators.

It is thought that the operation and advantages of my invention will bereadily understood from the preceding description taken in connectionwith the drawings.

Changes within the scope of the appended claims may be made in the formand proportion of some of the parts while their essential features areretained and the spirit of the invention is embodied. IIenee I do notdesire to be limited to the precise form of al1 the parts as shown,reserving the right to vary therefrom.

Having thus described the invention, what I claim isl. In a pue u mat ieapparatus for separating gold from sand, a series of alternatingdroppassages and uptake-passages, the latter having pockets attheirlower ends, and said droppassages having inclined bottomsConducting to said pockets, and said uptake -passages eoniinunieatingwith said drop-passages at their upper end and also at intermediatepoin'ls above the bottoms thereof, whereby eddies are formed in thelower portions of the drop-passages, for the purpose set forth,substantially as described.

2. In a pneumatic apparatus for separating geld from sand a primarypassage having` a pooket at its lower end an air-inlet port above saidpocket and an outlet-port in its upper side, in combination with asereen mechanism in the upper portion of said primary passage and aseries of alternating drop-passages and uptake-passages, one of theformer communicating with the outlet-port of the primary passage, andsaid uptake-passages.

having pockets at their lower ends Communicating therewith and with thelower sides of the drop-passages, and said uptake-passages comm unieatin g with said drop-passages

